New York — Invoking the prayer of his namesake St. Francis of Assisi, the pope officially entered the stormy politics of climate change on Thursday, issuing a much-anticipated pastoral letter that emphasized the moral imperative to “care for our common home,” urging global leaders to address “one of the principal challenges facing humanity in our day.”

It’s in many ways a test of the moral authority of the globally popular Pope Francis, who unveiled the papal encyclical “Laudito Si” – or “praise be to you” – after the Vatican’s unusually full-throated effort to promote the encyclical, which is considered a major, authoritative statement of the moral teachings of the Catholic church.

Especially in the United States, however, climate change and environmental concerns have ranked low on many Catholic bishops’ moral priorities. Instead, they have emphasized education and hot-button culture war issues such as abortion and same-sex marriage. Indeed, in a United Nations survey of millions of people around the world, the top priorities given were education, better job opportunities, health care, and honest governments. Environmental concerns and actions taken on climate change were at the bottom of a list of more than 15 top concerns.

But Pope Francis sounded a note of moral urgency on Thursday. “If present trends continue, this century may well witness extraordinary climate change and an unprecedented destruction of ecosystems, with serious consequences for all of us,” he wrote.

The 184-page encyclical also described a “technocratic paradigm” in which industrialized countries recklessly pursue profits at the expense of the environment and the globe’s poorest peoples, calling instead for a “bold cultural revolution” that would “recover the values and the great goals swept away by our unrestrained delusions of grandeur.”

“People may well have a growing ecological sensitivity but it has not succeeded in changing their harmful habits of consumption which, rather than decreasing, appear to be growing all the more,” Francis wrote.

Despite his popularity and the Vatican’s efforts to make “Laudito Si” one of the most anticipated encyclicals in decades, however, many wonder if the pope’s efforts can do much to change the politics of climate change.

“Most people, and most Catholics, view their politics through right or left secular lenses, not necessarily through what the pope has to say about anything,” says Charles Camosy, professor of theology and an expert on Christian bioethics at Fordham University in New York.

Indeed, one of the more famous encyclicals, “Humanae Vitae,” handed down by Pope Paul VI in 1968, issued strict teachings on human sexuality and contraception, teaching most current Catholics ignore.

And conservative Catholics, already suspicious of the pope’s emphasis on traditionally liberal social justice issues, have already begun to dismiss the church’s moral teachings on the environment.

“I hope I’m not going to get castigated for saying this by my priest back home, but I don’t get economic policy from my bishops or my cardinals or my pope,” said Republican presidential candidate Jeb Bush, a devout Catholic, at a campaign event in New Hampshire. Other Catholic Christians vying for the Republican nomination have also expressed skepticism about the human causes of climate change, including Marco Rubio, Bobby Jindal, and Rick Santorum.

And Catholic theologians point out that, despite the media attention Francis has garnered during his papacy, and his shift in tone in pastoral matters, the Catholic teachings about the environment and climate change go back to his predecessors John Paul II and Benedict XVI, who was known as the “green pope” for his environmental efforts.

“John Paul II stated very clearly the concern for ecology was not something optional, but was an essential part of Catholic faith,” says John Sniegocki, professor of theology at Xavier University in Cincinnati, Ohio.

Still, “Laudito Si” is the first papal encyclical devoted entirely to the moral imperatives of caring for the environment, and it comes as global leaders are preparing for the major UN climate summit in Paris at the end of the year.

“Though climate change is a very hyper-partisan issue, I’m not sure it’s always framed as a moral issue as much as an economic debate about how to solve these problems, whether through regulation or private enterprize solutions,” says Christopher Vogt, chair of the department of theology and religious studies at St. John’s University in New York, who is in Rome during the events surrounding the release of the encyclical.

“I’m hopeful that raising it as a moral issue, and a spiritual issue, it might bring additional people into the debate who otherwise had not been interested or engaged in climate change or environmental issues,” Professor Vogt continued.

But observers caution that the papal letter may not have the impact some may expect.

“Given the transnational nature of the church, and the impact this will have on dioceses all over the world, and in almost every culture, we can hope for a new momentum that will have a long term impact,” says Professor Camosy. “But I do think people who are expecting short term changes will be disappointed.”

But Pope Francis, who chose his name in honor of the saint famously known for his theology of creation and love for nature as a “sister” of humankind, is working to make climate change at the top of the Catholic church’s moral agenda moving forward.

“Obstructionist attitudes, even on the part of believers, can range from denial of the problem to indifference, nonchalant resignation or blind confidence in technical solutions,” Francis wrote. “We require a new and universal solidarity.”